class Todo:
    current_todo_id = 0
    @ classmethod
    def next_id(cls):

        Todo.current_todo_id += 1
        return  Todo.current_todo_id

    def __init__(self,title:str='',completed=False,id:int=0):
        self.id=id if id>0 else Todo.next_id()
        self.title=title
        self.completed=completed